The Z-5500 has a Night Mode feature built in that enables you to eliminate the louder boom sounds.

NOTE: This feature only works in the Dolby Digital setting

This is especially useful if you are listening to music or watching a movie at times when other members of your household (or your neighbors) might be sleeping.

To enable Night Mode,

1. Press the Settings button on the front of the control pod.
2. Cycle through the settings and choose Night Mode.
3. Select a level (Max, Normal, Off) by rotating the knob on the front of the control pod.

The Night Mode feature settings (Max, Normal and Off ) are shown below: